Re: "in-program" backup facility
- To: mathgroup at smc.vnet.net
- Subject: [mg111883] Re: "in-program" backup facility
- From: David Bailey <dave at removedbailey.co.uk>
- Date: Tue, 17 Aug 2010 01:20:23 -0400 (EDT)
- References: <i4b1tv$b52$1@smc.vnet.net>
On 16/08/10 10:55, Bill Rowe wrote: > On 8/15/10 at 7:36 AM, plindsay.0 at gmail.com (peter) wrote: > >> I've seen a few posts about this and I'm wondering if I am missing >> the point [ again ]. Surely folks are managing their own backups - >> perhaps using "Time Machine" on the mac or whatever. The arguments >> in favour or regular backups surely extend beyond the use of >> Mathematica and apply generally to the use of a personal computer ? > > Undoubtedly, such backups are done by many users here. But, such > backups don't entirely resolve the issue. > > Time Machine and the like backup the entire hard drive. The > default interval for Time Machine is 1 hour. With Mathematica, a > substantial amount of work can be lost when restoring a notebook > to what it was 1 hour ago. > > And note, Time Machine backs up the file as it exists on the > hard drive. If you have not saved your work periodically, the > file backed up by Time Machine could be quite a bit more than 1 > hour old. > > Creating some sort of script to automate periodically saving the > state of a notebook and decreasing the interval Time Machine > uses for backups isn't a viable solution either. If you decrease > the interval between backups enough, then Time Machine will be > perpetually running and never complete a backup. Further, with a > scheme to automatically save notebooks there will be the chance > Time Machine will be writing the notebook to the backup at the > same time it is being modified (saved) by the automated save > script. And the probability of this occurring clearly increases > as the interval between backups is decreased. The result of such > collisions will be the copy of the notebook in the Time Machine > backup won't be stable and likely is unusable. > > Programs designed to backup all files that have changed on a > hard drive really aren't replacements for what is being asked for. > > I'd say some sort of 'nag' function that just reminded the user that he had been working on a notebook for x minutes, and wouldn't he like to save. An automatic save can easily happen at the worst possible moment - say half way through a long series of find/replace operations! I like control over what is going on. David Bailey http://www.dbaileyconsultancy.co.uk